SPUG: trinary ? operator

Daryn Nakhuda daryn at marinated.org
Fri Jan 25 19:41:55 CST 2002


what are you trying to do exactly?

what you typed is equivalent to:

if ($ok) {
    $a = $b;
}
else {
    $a = $c;
}

if you meant to do

if ($a == $ok) {
   $something = $b;
}
else {
   $something = $c;
}

that'd be 

$something = ($a == $ok) ? $b : $c;




On Fri, 25 Jan 2002, Meryll Larkin wrote:

> 1/25/02
> 
> Hi Folks, 
> 
> I'm using Active Perl5.005_03 on Windows98 and 5.6.1
> on Windows2000 professional edition and I can't get
> the trinary ? operator to work.  Does anyone have any
> experience with this in Windows?  Does my syntax need
> correcting?
> 
> On pg 92 of Programming Perl (2nd Edition) an example
> of the trinary operator is given:
> 
> $a = $ok ? $b : $c;
> 
> I find if I use this syntax, I get an assignment to $b
> (the "true" choice) because $a = $ok has a single =
> instead of ==.  
> 
> If I try to use == I don't get an error, the entire
> line seems to be ignored.  
> 
> If I use strings and use "eq" the line is also
> ignored.
> 
> Turning on -w gets me this error:
> Useless use of private variable in void context.
> Useless use of private variable in void context.
> (yes, twice, I assume it refers to $b and $c)
> 
> help?
> 
> Meryll
> 
> 
> 
> 
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